<!DOCTYPE html>
<html>
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		* {
			margin: 0;
			padding: 0;
		}

		.c-items .item-1 {
			width: 50%;
			background-color: red;
		}

		.c-items .item-2 {
			width: 50%;
			background-color: blue;
		}
		
	</style>
</head>
<body>
	
	<div class="c-items"><div class="item item-1">item 1</div><div class="item item-2">item 1</div></div>

</body>
</html>